The obese gene is expressed in lean littermates of the genetically obese mouse (C57BL/6J ob/ob)

Am J Physiol. 1999 Apr;276(4):E762-5. doi: 10.1152/ajpendo.1999.276.4.E762.


Some individuals of the mixed group of "lean" littermates (+/ob and +/+) of (C57BL/6J ob/ob) often suggest phenotypic characteristics of ob/ob animals. Therefore, it was of interest to determine whether expression of the ob gene had physiological significance in +/ob animals. Body weight (BW), fasting blood glucose (FBG), and body core temperature (Tr) were monitored between 62 and 364 days of age in +/+ and +/ob mice. Among females but not males, +/ob mice were heavier (P = 0.003) and FBG levels were greater (P = 0.04) than in +/+ animals. Comparison of Tr indicated differences suggesting falling Tr in +/ob but rising Tr in +/+ mice with age in males but not females. Multivariate analysis of variance yielded genotype effects for both males (P = 0.002) and females (P = 0.02). BW, FBG, and Tr alone were sufficient at the 75% level for genotypic characterization and separation of +/? animals as +/ob or +/+; clearly, expression of the ob gene in heterozygotes of the +/ob animal may make the mixed +/? group inappropriate as lean controls.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aging / physiology*
  • Animals
  • Blood Glucose / metabolism*
  • Body Temperature*
  • Body Weight / genetics*
  • Crosses, Genetic
  • Female
  • Genetic Carrier Screening
  • Genotype
  • Homozygote
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Obese
  • Obesity / genetics*
  • Sex Characteristics


  • Blood Glucose